Phylogenetic and Phylogeographic Analysis of Iberian Lynx Populations

Transcription

1 Journal of Heredity 2004:95(1):19 28 DOI: /jhered/esh006 ª 2004 The American Genetic Association Phylogenetic and Phylogeographic Analysis of Iberian Lynx Populations W. E. JOHNSON, J. A. GODOY, F. PALOMARES, M. DELIBES, M. FERNANDES, E. REVILLA, AND S. J. O BRIEN From the Laboratory of Genomic Diversity, National Cancer Institute-FCRDC, Frederick, MD (Johnson and O Brien), Department of Applied Biology, Estación Biológica de Doñana, CSIC, Avda. María Luisa s/n, 41013, Sevilla, Spain (Godoy, Palomares, Delibes, and Revilla), and Instituto da Conservac ão da Natureza, Rua Filipe Folque, 46, 28, Lisboa, Portugal (Fernandes). E. Revilla is currently at the Department of Ecological Modeling, UFZ-Center for Environmental Research, PF 2, D Leipzig, Germany. The research was supported by DGICYT and DGES (projects PB , PB , and PB ), Consejería de Medio Ambiente de la Junta de Andalucía, Instituto Nacional para la Conservacion de la Naturaleza, and US-Spain Joint Commission for Scientific and Technological Cooperation. We thank A. E. Pires, A. Piriz, S. Cevario, V. David, M. Menotti-Raymond, E. Eizirik, J. Martenson, J. H. Kim, A. Garfinkel, J. Page, C. Ferris, and E. Carney for advice and support in the laboratory and J. Calzada, J. M. Fedriani, P. Ferreras, and J. C. Rivilla for assistance in the capture of lynx. Museo Nacional de Ciencias Naturales, Doñana Biological Station scientific collection, Doñana National Park, and Instituto da Conservac ão da Natureza of Portugal provided samples of museum specimens. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government. Address correspondence to W. E. Johnson at the address above. Abstract The Iberian lynx (Lynx pardinus), one of the world s most endangered cat species, is vulnerable due to habitat loss, increased fragmentation of populations, and precipitous demographic reductions. An understanding of Iberian lynx evolutionary history is necessary to develop rational management plans for the species. Our objectives were to assess Iberian lynx genetic diversity at three evolutionary timescales. First we analyzed mitochondrial DNA (mtdna) sequence variation to position the Iberian lynx relative to other species of the genus Lynx. We then assessed the pattern of mtdna variation of isolated populations across the Iberian Peninsula. Finally we estimated levels of gene flow between two of the most important remaining lynx populations (Doñana National Park and the Sierra Morena Mountains) and characterized the extent of microsatellite locus variation in these populations. Phylogenetic analyses of 1613 bp of mtdna sequence variation supports the hypothesis that the Iberian lynx, Eurasian lynx, and Canadian lynx diverged within a short time period around million years ago, and that the Iberian lynx and Eurasian lynx are sister taxa. Relative to most other felid species, genetic variation in mtdna genes and nuclear microsatellites were reduced in Iberian lynx, suggesting that they experienced a fairly severe demographic bottleneck. In addition, the effects of more recent reductions in gene flow and population size are being manifested in local patterns of molecular genetic variation. These data, combined with recent studies modeling the viability of Iberian lynx populations, should provide greater urgency for the development and implementation of rational in situ and ex situ conservation plans. The Iberian lynx (Lynx pardinus), the largest remaining cat species in southwestern Europe, is one of the world s most endangered felids (Nowell and Jackson 1996). The genus Lynx, including the Iberian lynx, bobcat (L. rufus), Canadian lynx (L. canadensis), and Eurasian lynx (L. lynx) descend from a common ancestor that diverged from other cat species more than 6 million years ago ( Johnson and O Brien 1997). These four Lynx species have almost completely disjunctive distributions and occupy different habitats. However, they share numerous physical characteristics and are distinguished primarily by their relative sizes (Nowell and Jackson 1996) and a few cranial or postcranial skeletal measurements (Garcia-Perea 1992). There has been consistent support for a monophyletic ancestry for the four species from morphological (Nowak 1999) and DNA-based analyses ( Janczewski et al. 1995; Johnson et al. 1996; Johnson and O Brien 1997; Pecon- Slattery and O Brien 1998). However, the hierarchical relationships among lynx species and their recognition as unique species have been debated. 19

2 Journal of Heredity 2004:95(1) Fossil records suggest that lynx species originated in North America (MacFadden and Galiano 1981; Martin 1989). The bobcat appears to represent the earliest lineage to diverge (Johnson and O Brien 1997), but subsequent evolutionary history is less clear. The Iberian lynx and Eurasian lynx may be derived from an ancestral lynx species (Lynx issiodorensis) whose remains have been found in China (Wederlin 1981). The Canadian and Eurasian lynx have been hypothesized to be sister taxa (Wederlin 1981). The Iberian lynx and Eurasian lynx were both found in central Europe during the Pleistocene (Kurten 1968; Kurten and Grandqvist 1987), but may never have had significantly overlapping geographic ranges. The distribution and population sizes of the Eurasian and Iberian lynx have been reduced significantly during the last two centuries. The Eurasian lynx was extirpated from most of central and southern Europe during the 19th century (Breitenmoser and Breitenmoser-Wursten 1990). Similarly, by the beginning of the 20th century the Iberian lynx was rare in northern Spain and by the 1960s its range was essentially limited to isolated populations in the southwestern portion of the peninsula (Rodriguez and Delibes 1990). By the 1990s, it was estimated that no more than 1000 lynx were restricted to fewer than 50 disjunct breeding areas that could be grouped into less than 10 distinct subpopulations (Castro and Palma 1996; Rodriguez and Delibes 1992). Only two of these subpopulations, Sierra Morena and Montes de Toledo (Figure 1) inhabit areas larger than 2000 km 2, which is of major concern since between 1960 and 1988 Iberian lynx are presumed to have disappeared from most of the remaining small habitat patches (from 91% of the areas smaller than 1000 km 2 ). This corresponds to an 80% reduction in occupied range (Rodriguez and Delibes 1990). However, current geographical limits and population sizes are not well known and continued loss of habitat and the disappearance of lynx from previously occupied areas suggests that fewer than 500 individuals may now remain (Beltrán and Delibes 1994; Palomares et al. 2000; Pires and Fernandes 2003). The best known of the Iberian lynx populations inhabits Doñana National Park, Andalusia, where field data on the species have been collected since the 1950s and radiotracking studies have been conducted for more than 15 years (e.g., Ferreras et al. 1997; Gaona et al. 1998; Palomares et al. 1991, 2001). The Doñana metapopulation (1500 km 2 )of approximately individuals currently is distributed in at least four distinct areas that were last completely connected during the middle of the last century. Within the Doñana metapopulation, the population occupying the protected parkland areas is relatively stable, while mortality in the lessprotected areas is higher, especially among dispersing animals (70 85% mortality rate) (Ferreras et al. 1992; Gaona et al. 1998). Because of its small numbers and isolation, the Doñana metapopulation would be susceptible to low levels of genetic variation (Beltrán and Delibes 1993). The Doñana metapopulation has been isolated from other Iberian lynx populations for at least 50 years by an expanse of more than 50 km of croplands to the north and almost 30 km of comparatively dense human settlements to the west (Rodriguez and Delibes 1992). The nearest lynx populations are found in the Sierra Morena Mountains (Figure 1), where several of the largest remaining lynx metapopulations are suspected to still exist. This mountain range, perhaps one of the keys to the future preservation of the Iberian lynx, has received increasing attention by conservationist and resource managers. The objectives of this study were to quantify the evolutionary relationship of the Iberian lynx with the other Lynx species using mtdna sequence variation, describe patterns of lynx mtdna variation across the Iberian peninsula, and compare patterns of microsatellite size variation and estimate gene flow between the important lynx populations of Doñana and Sierra Morena. An improved understanding of patterns of Iberian lynx molecular genetic variation and recent evolutionary history is necessary to develop rational management plans for the species (Vargas 2000) and provide further insights into the biogeographical history of the Iberian peninsula. Methods DNA Extraction Lynx DNA was extracted from blood and tissue samples from 20 wild animals captured or found dead during capturing and radio-tracking of lynx from 1985 to 2000, and from 35 tissue and skin samples in scientific collections from seven metapopulations throughout the range of the Iberian lynx (Table 1). Blood samples were stored in four volumes of lysis buffer (0.1 M Tris-HCl ph 8.0; 0.1 M Na- EDTA; 0.01 M NaCl, 0.5% SDS) and tissue samples were kept frozen or at room temperature in a dimethyl sulfoxide (DMSO)-salt solution (20% DMSO, 0.25M Na-EDTA, and NaCl to saturation, ph 8.0). From museums specimens, approximately 1 cm 2 of skin was cut with a sterile scalpel after superficial cleaning with 10% commercial bleach, distilled water, and 70% ethanol. DNA extractions of museum materials were conducted in a dedicated room along with extraction blanks to monitor for contamination. DNA was extracted following standard proteinase K/phenol chloroform protocols (Sambrook et al. 1989); for museum skin extractions, several prewashes with NTE ph 9.0 (NaCl 10 mm; Tris base 50 mm; EDTA 20 mm) were included to remove possible enzyme inhibitors. For comparative purposes we used DNA extracted using similar techniques in previous studies from three European lynx (Lly 12, 15, and 16), two Canadian lynx (Lca 3 and 7), five bobcat (Lru 6, 26, 48, 68, and 73), two marbled cats (Pardofelis marmorata) (Pma 4 and 5), and one clouded leopard (Neofelis nebulosa) (Nne 80) ( Johnson and O Brien 1997). Mitochondrial DNA Markers Sequence variation in portions of five mtdna genes (ATPase-8, 16S rrna, 12S rrna, NADH-5, and cytochrome b) was assessed in four Iberian lynx, three European lynx, two Canadian lynx, and five bobcat, along with two 20

3 Johnson et al. Phylogenetic and Phylogeographic Analysis of Iberian Lynx Populations Figure 1. Geographic distribution of the Iberian lynx populations sampled in the study modified after Rodriguez and Delibes (1992) and Castro and Palma (1996). In Spain, the data represent estimated distributions from the 1980s and in Portugal the data are from The distribution of mtdna haplotypes in each of the major populations (which are labeled following Table 1) are represented in pie charts, along with the number of individuals sampled from each population. marbled cats and a clouded leopard as outgroups, to assess the uniqueness of the Iberian lynx and to determine the evolutionary relationships among Lynx species. A larger set of Iberian lynx from across the Iberian peninsula (43 individuals from seven metapopulations; Table 1) was used to characterize patterns of mtdna sequence variation in three mtdna fragments: 191 of ATPase-8 gene, and 195 and 89 bp of two noncontiguous fragments of the hypervariable segment 1 of the control region (Kim et al. 2001). DNA amplification reactions contained 67 mm Tris-HCl ph 8.0, 16 mm (NH 4 ) 2 SO 4, 2.5 mm MgCl 2, 0.01% Tween- 20, 0.2 mm dntps, 1 lm of each primer, 0.5 U of Taq polymerase and ng of total DNA for blood samples or 5 ll of museum skin extracts as template. Polymerase chain reaction (PCR) primers and primer conditions have been published previously ( Janczewski et al. 1995; Johnson and O Brien 1997; Johnson et al. 1998; Palomares et al. 2002). Bovine serum albumin (BSA) was included at a concentration of 0.1 lg/ll for amplification of blood DNA and 0.8 lg/ll for museum and skin samples. Amplification reactions were performed in an MJ Research (Boston) thermocycler, model PTC-100, at an initial denaturation cycle of 948C for 2 min, followed by 35 cycles of denaturation at 928C for 30 s, annealing at C (depending on primers) for 30 s, extension at 728C for 30 s, and were completed with a final extension at 728C for 5 min. Positive and negative DNA controls were included with each set of PCRs. Amplification products were separated by 21

4 Journal of Heredity 2004:95(1) Table 1. Sample identifier, sample type, population and metapopulation of origin, nucleotide residue at positions 8672 and 16,804 (domestic cat sequence, López et al. 1996) and mtdna haplotype for gene segments of ATP-8, control region 1 (CR1), and control region 2 (CR2) combined Sample identification Tissue Population Metapopulation ,804 mtdna haplotype Source Barro* Blood Coto del Rey Doñana C T B Authors Borja* Blood Coto del Rey Doñana Authors Escarlata* Blood Coto del Rey Doñana Authors Gloria* Blood Coto del Rey Doñana C T B Authors Maki* Blood Coto del Rey Doñana Authors Nuria* Blood Coto del Rey Doñana C T B Authors Vampi* Blood Coto del Rey Doñana Authors Skin Coto del Rey Doñana C T B EBD Anibal* Blood Vera Doñana Authors Celia* Blood Vera Doñana Authors Cova* Muscle Vera Doñana C T B PND Isabel* Blood Vera Doñana PND Jabata* Tissue Vera Doñana PND Juanito* Muscle Vera Doñana C T B Authors Navidad* Blood Vera Doñana Authors Understand* Tissue Vera Doñana PND Skin Unknown Doñana C T B EBD Skin Unknown Doñana C T B EBD Ibiza* Blood Sierra Morena Eastern Sierra Morena Authors Morena* Blood Sierra Morena Eastern Sierra Morena T T A PND Píriz* Blood Sierra Morena Eastern Sierra Morena T T A Authors Sierra* Blood Sierra Morena Eastern Sierra Morena Authors Sofía* Blood Sierra Morena Eastern Sierra Morena T T A Authors Skin Sierra Morena Eastern Sierra Morena C T B EBD 5452 Skin Jaen Eastern Sierra Morena T T A MCNM 5463 Skin Jaen Eastern Sierra Morena T MCNM 1387 Skin Andujar Jaen Eastern Sierra Morena T T A EBD 1732 Skin Andujar Jaen Eastern Sierra Morena T EBD Skin Andujar Jaen Eastern Sierra Morena T T A EBD Skin Andujar Jaen Eastern Sierra Morena T T A EBD c28 Skin Malcata Sierra Gata Malcata C T B ICN 1376 Skin Salamanca Sierra Gata C T B EBD c21 Skin Penamacor Sierra Gata Malcata C T B ICN c22 Skin Penamacor Sierra Gata Malcata T ICN 5456 Skin Montes de Toledo Montes de Toledo T MCNM 5458 Skin Montes de Toledo Montes de Toledo T MCNM 5446 Skin Los Yebenes To Montes de Toledo T T A MCNM 5450 Skin Los Yebenes To Montes de Toledo T T A MCNM 5451 Skin Los Yebenes To Montes de Toledo T MCNM 5462 Skin Los Yebenes To Montes de Toledo T T A MCNM 5465 Skin Los Yebenes To Montes de Toledo T MCNM 5467 Skin Los Yebenes To Montes de Toledo T T A MCNM 5470 Skin Los Yebenes To Montes de Toledo T T A MCNM 5449 Skin Toledo Montes de Toledo T T A MCNM 5454 Skin Toledo Montes de Toledo T T A MCNM 5466 Skin Toledo Montes de Toledo T MCNM 5468 Skin Toledo Montes de Toledo T MCNM 5469 Skin Toledo Montes de Toledo T MCNM 1373 Skin Huelva Western Sierra Morena T C C EBD 1377 Skin Huelva Western Sierra Morena T C C EBD c14 Skin Alcáçovas Sado Valley Algarve C T B ICN C32 Skin Alcácer Sado Valley Algarve C T B ICN 846 Skin Avila Gredos o Alto Alberche T T A EBD Skin Unknown Unknown T T A EBD C3 Skin Unknown Portugal C T B ICN Metapopulations are also depicted on the map in Figure 1. Samples used in microsatellite analyses are marked with an asterisk (*) and samples from the Museo de Ciencias Naturales de Madrid (MCNM), Estacion Biologica de Doñana (EBD), Parque Nacional de Doñana (PND), and the Instituto da Conservação da Natureza (ICN) are noted. The additional samples were collected by several of the authors during field studies. 22

5 Johnson et al. Phylogenetic and Phylogeographic Analysis of Iberian Lynx Populations electrophoresis in 2 3% agarose gels in TBE buffer (89 mm Tris base, 89 mm boric acid, 2 mm EDTA) in the presence of 0.5 mg/l EtBr. Gels were visualized under ultraviolet light and photographed with a digital image system (Eastman Kodak). Polymerase chain reaction products were cleaned by ultrafiltration through Centricon-100 (Millipore Corp.) and sequenced on an automated DNA sequencer (ABI 377) using the BigDye Terminator Cycle Sequencing Kit following the manufacturer s instructions (Applied Biosystems). Sequences were edited, assembled, and aligned using the program Sequencher (Gene Codes Corp.) and submitted to GenBank (accession numbers AY AY499337). Microsatellite Markers Twenty-eight microsatellite loci (Fca43, 71, 75, 80, 82, 90, 96, 97, 98, 102S, 117, 161, 132, 193, 232, 272, 369, 391, 424, 441, 453, 476, 493, 519, 547, 566, 571, 698) from 11 of the 19 domestic cat chromosomes were characterized in 20 presumably unrelated lynx from two populations (Vera and Coto del Rey) in Doñana and in Valquemado from Sierra Morena (Table 1) following previously described PCR amplification conditions (Menotti-Raymond et al. 1997, 1999). All microsatellites were dinucleotide repeats except FCA391, FCA441, and FCA453, which had tetranucleotide repeats. Of the 28 loci, 22 were unlinked or at least 20 cm apart in the domestic cat and are presumed to be unlinked in Iberian lynx (Menotti-Raymond et al. 1999; submitted). Three pairs of loci were linked at distances of 9 cm (Fca75 and Fca96), 8 cm (Fca90 and Fca566), and 1 cm (Fca132 and Fca369). The dye-labeled PCR products of the microsatellite primer sets were pooled and diluted together based on size range and fluorescent dye so that three to six loci could be multiplexed and electrophoresed and subsequently analyzed in an ABI 377 automated sequencer. Microsatellite allele sizes were estimated by comparison with a GS350 TAMRA (ABI) internal size standard. Data were collected and analyzed using the ABI programs GENESCAN (version ) and GENOTYPER (version 1.1). PCR product length was used as a surrogate for actual repeat length (Ellegren et al. 1995). branch swapping. The ME approach employed a neighborjoining tree (Saitou and Nei 1987) constructed from Kimura two-parameter distances, with the proportion of invariable sites estimated to be from the empirical data and the rate for variable sites assumed to follow a gamma distribution. After testing and comparing several models, ML analysis was done using the HKY85 model (Hasegawa et al. 1985) with parameters estimated from the dataset. The reliability of the nodes in each of the analyses was assessed by 100 bootstrap iterations (Hillis and Bull 1993). Mitochondrial DNA sequence variation across Iberian lynx was assessed in 452 bp from three mitochondrial gene fragments (ATP-8 and two control region segments). Measures of mtdna sequence variation were estimated using MEGA 2.1 (Kumar et al. 2001). The divergence date among European lynx, Iberian lynx, and Canadian lynx was estimated by averaging all pairwise (p) distances among haplotypes. Feline-specific mtdna divergence rates of 1.39% (ATPase-8), 0.97% (cytochrome b), 1.22% (NADH- 5), 0.88% (12S rrna), and 0.97% (16S rrna), as developed by López et al. (1997), were weighted based on the number of base pairs used for each gene to obtain a composite divergence rate of 1.04% per million years. Estimates of microsatellite size variation, such as average expected heterozygosity, average variance, number of unique alleles, and average number of repeats, were derived from the program MICROSAT (version 1.5) (Minch et al. 1995). Deviations from Hardy-Weinberg equilibrium, following the procedure of Guo and Thompson (1992), and estimates of population subdivision, F ST, and R ST analogs (Michalakis and Excoffier 1996; Slatkin 1995; Weir and Cockerham 1984) were derived using ARLEQUIN (Schneider et al. 2000). Pairwise genetic distances among individuals using the composite microsatellite genotypes were estimated using the proportion of shared alleles (Dps) algorithm with a (1 M) correction as implemented in the program MICROSAT (version 1.5) (Minch et al. 1995). A phylogenetic tree was constructed from the Dps distance matrix using the Neighbor option of the program PHYLIP (version 3.572) (Felsenstein 1993) and was drawn using the program TREEVIEW (version 1.5) (Page 1996). Phylogenetic and Population Analyses Phylogenetic comparisons among lynx species were conducted with sequence variation from five mtdna gene fragments (ATPase-8, cytochrome b, 12S rrna, 16S rrna, and NADH-5). Marbled cat and clouded leopard sequences were included for outgroup comparisons. Sequences from each of the mtdna gene fragments were combined into a contig of 1613 bp after separate analysis of each gene fragment (Huelsenbeck et al. 1996). Phylogenetic relationships among the haplotypes were estimated using minimum evolution (ME), maximum likelihood (ML), and maximum parsimony (MP) methods using PAUP* (Swofford 2001). An MP analysis was conducted using a heuristic search, with random addition of taxa and tree-bisection reconnection Results and Discussion Phylogenetic Analyses Analysis of the evolutionary relationships among the four Lynx species from 1613 bp of sequence from five mtdna genes (ATPase-8, 16S rrna, 12S rrna, NADH-5, and cytochrome b) confirmed the taxonomic status of the Iberian lynx as a unique species with a relatively long evolutionary history (Beltrán et al. 1996). Among the four Lynx species, there were 158 variable sites, of which 141 were parsimoniously informative (Figure 2). There were two Iberian lynx haplotypes from four individuals, two haplotypes from three European lynx, two haplotypes from two Canadian lynx, and three haplotypes from five bobcats, along with two marbled 23

6 Journal of Heredity 2004:95(1) Figure 2. Variable sites among Iberian lynx (Lyp), Eurasian lynx (Lly), Canadian lynx (Lca), Bobcat (Lru), and Marbled cat (Pma) for 12S, 16S, Atp8, NADH-5, and CytB mtdna gene fragments. Sample codes refer to the individual Iberian lynx (Lyp), European lynx (Lly), Canadian lynx (Lca), bobcat (Lru), and marbled cat (Pma) depicted in the phylogenetic tree of Figure 3. Position numbers correspond to the complete domestic cat mtdna sequence (López et al. 1996). cat haplotypes (Figures 2 and 3). Among the Lynx species, using the marbled cat and clouded leopard as outgroup species, there was strong support (96 100% bootstrap support from MP, ME, and ML phylogenetic analyses) that the bobcat was the most basal lineage, or the first to diverge (Figure 3). The relative relationships among the Iberian lynx, Eurasian lynx, and Canadian lynx were less well defined, with bootstrap support varying depending upon the method of analysis. However, each analysis suggested that the Iberian lynx and Eurasian lynx were sister taxa (58% MP, 50% ME, and 60% ML bootstrap support) that together shared a common ancestor with the Canadian lynx. This finding differs from the findings of Beltrán et al. (1996) that the Iberian lynx and the Canadian lynx were sister taxa. The pairwise genetic distances among these three species were low, ranging from 53 to 58 bp (of 1639 bp), or %. 24

7 Johnson et al. Phylogenetic and Phylogeographic Analysis of Iberian Lynx Populations O Brien 1997), the rapid divergence among the three lynx species occurred around million years ago. Figure 3. Phylogenetic relationships among Lynx species and outgroup Felid species from 1639 bp of sequence from six combined mtdna gene fragments. Depicted is a maximum likelihood phlylogenetic tree constructed with the HKY85 model using empirical nucleotide frequencies, a transition/ transversion ratio of 12.6, an assumed proportion of invariable sites of 0.295, and a shape parameter (a) of Above the branches are bootstrap values (100 iterations) for maximum parsimony/minimum evolution/maximum likelihood analyses and below the branches are the number of base substitutions/ number of homoplasies from the maximum parsimony analyses. Maximum parsimony trees were obtained via a tree-bisection reconnection algorithm with starting trees obtained by stepwise addition. Minimum evolution trees were depicted using the neighbor-joining algorithm using Kimura two-parameter distances. These results confirm that the Iberian lynx is a unique species and that the Eurasian lynx, Canadian lynx, and Iberian lynx all speciated or diverged into monophyletic lineages around the same time. Assuming an mtdna divergence rate of 1.04% per million years, based on a feline gene-specific mtdna mutation rate (Culver et al. 2000; Johnson and Mitochondrial DNA Diversity Mitochondrial DNA sequence variation across 46 Iberian lynx from throughout most of their distribution on the Iberian Peninsula (from seven metapopulations) was assessed in 452 bp from three mitochondrial gene fragments (positions 8657 to 8818, as numbered in the complete Felis catus mtdna sequence of López et al. [1996] and two control region segments). Because many of these samples were hides from museums, not all individuals amplified for each of the three gene segments. MtDNA diversity among Iberian lynx was low (Figure 2 and Table 2). Among the 46 Iberian lynx sequenced, there were two variable sites in 452 bp from three mtdna fragments that defined three haplotypes (A, B, and C). At position number 8672 (nucleotide numbers from the reference domestic cat sequence; López et al. 1996) in the ATP-8 gene, there was either a T (haplotypes A and C) or a C (haplotype B). At position number 16,804 of the control region, two individuals from the Sado-Algarve metapopulation had a C (haplotype C), compared with T for the other lynx (haplotypes A and B). All eight Iberian lynx from the southernmost metapopulation of the Doñana National Park area had haplotype B, as did one lynx from eastern Sierra Morena, two lynx from Sado-Algarve, Portugal, and four lynx from Sierra Gata Malcata, Portugal. Haplotype A was found in the easternmost metapopulations of eastern Sierra Morena and Montes de Toledo. Haplotype C was restricted to the two samples from the western Sierra Morena metapopulation (Figure 1). The Iberian lynx displayed among the lowest levels of mtdna diversity that have been documented for a felid species, as is apparent from a comparison of the sequence variation across the roughly 880 bp from the mtdna gene fragments of NADH-5, 16S, and ATP-8 among several cat species (Table 2). This overall pattern suggests that Iberian lynx is descended from a recent founder effect or a population bottleneck. In addition, the disjunct distribution of the haplotypes (Figure 1) suggests that recent isolation of populations and reduced population sizes may have led to haplotype fixation. All three haplotypes were found between Table 2. Measures of mtdna sequence variation in the same combined fragments of NADH-5 (positions 12,647 to 12,946 from the complete Felis catus mtdna sequence of López et al. 1996), 16S (positions 2904 to 3285), and ATP-8 (positions 8657 to 8818) (a total of about 880 bp) among eight felid species Species Sample size Number of variable sites Number of haplotypes p Reference Puma (Puma concolor) Culver et al. (2000) Andean mountain cat (Oreailurus jacobita) Johnson et al. (1998) Tigrina (Leopardus tigrinus) Johnson et al. (1999) Pampas cat (Lynchailurus colocolo) Johnson et al. (1999) Geoffroy s cat (Oncifelis geoffroyi) Johnson et al. (1999) Kodkod (Oncifelis guigna) Johnson et al. (1999) Iberian lynx (Lynx pardinus) This study 25

8 Journal of Heredity 2004:95(1) Table 3. Measures of variation in 28 microsatellites in three Iberian lynx populations Sample size Percent polymorphic Percent observed heterozygosity Microsatellite variance Average allele size range Mean number alleles per locus Unique alleles Sierra Morena Doñana a Coto del Rey b, 3c Vera b, 3c Total a Relative to Sierra Morena. b Relative to Sierra Morena and Vera population (or Coto del Rey). c Between Coto del Rey and Vera. the eastern and western Sierra Morena metapopulations, in south-central Spain, in the middle of the historic distribution of lynx. Microsatellite Diversity The amount of microsatellite allele variation among Iberian lynx from the two Doñana populations was very similar (Table 3). Average observed heterozygosity was 26.7% in Coto del Rey and 29.4% in Vera and the average range in allele sizes in both populations was Estimates of microsatellite size variation were slightly higher in Sierra Morena than in Doñana (Table 3), including a larger percentage of polymorphic microsatellite loci (75% versus 71.4%). Overall, this amount of microsatellite variation is less than or comparable to that seen in felids such as cheetahs and North American pumas (Table 4), which experienced demographic bottlenecks around the time of the Pleistocene ice ages (Culver et al. 2000). The populations of Coto del Rey and Vera each had three unique alleles that were not observed in the other. In contrast, the metapopulation of Doñana had 19 unique alleles not observed in Sierra Morena, and Sierra Morena had 26 that were not seen in Doñana (Table 3). These differences were reflected in the analyses of population structure. F ST values among all three populations were significant (P,.05), but were highest between Sierra Morena and the two Doñana populations (0.378 with Coto del Rey and with Vera; between Coto del Rey and Vera). R ST values were only significant between Sierra Morena and Coto de Rey (R ST ¼ 0.576). However, several loci were significantly out of Hardy- Weinberg equilibrium in the Doñana metapopulation and in the Vera population when analyzed separately. In each case there was a deficiency of heterozygotes that may reflect inbreeding, disproportionate reproductive success of some individuals, or some degree of allele dropout. The pattern of differentiation among populations can be visualized in the dendrograms resulting from the phylogenetic analyses of individual composite genotypes (Figure 4). The six lynx from Sierra Morena are separated from Doñana individuals with high bootstrap support (93%). In comparison, lynx from the two Doñana populations were intermixed, although animals from the same population tended to be most closely linked with another individual from the same population. During the last 15 years there has been only one documented instance of a lynx that moved from Vera to Coto del Rey and another three cases of lynx moving from Coto del Rey to Vera (Ferreras 2001). Of these, only the lynx that emigrated to Coto del Rey established a territory and successfully bred. Evolutionary Implications Our estimation, based on mtdna sequence variation and a felid-specific divergence rate for these genes, that L. pardinus diverged as an unique species million years ago is compatible with paleontological evidence that the Lynx species inhabiting Europe during the late Pliocene and early Pleistocene was probably a common ancestor (frequently called L. issiodorensis) of three current Lynx species, L. lynx, L. pardinus, and L. canadensis (Kurten 1968; Werderlin 1981). The earliest paleontological evidence of L. pardinus has been found in France from around several hundred thousand years ago, in the Middle Pleistocene and later (Kurten and Table 4. Measures of microsatellite size variation at 12 loci among populations of four felid species Population Sample size Loci typed Observed heterozygosity Mean microsatellite variance Number of alleles/locus Reference Asian lion Driscoll et al. (2002) Lion, Crater Driscoll et al. (2002) Lion, Serengeti Driscoll et al. (2002) Cheetah, East Africa Driscoll et al. (2002) Cheetah, West Africa Driscoll et al. (2002) Puma, Big Cypress Swamp Driscoll et al. (2002) Puma, Idaho Driscoll et al. (2002) Puma, South America Driscoll et al. (2002) Iberian lynx, Doñana This study Iberian lynx, Sierra Morena This study 26

9 Johnson et al. Phylogenetic and Phylogeographic Analysis of Iberian Lynx Populations We recommend that any future movement of animals in the wild or the establishment of captive programs be accompanied by more thorough analysis of the population sizes and levels of microsatellite variation in the other lynx metapopulations in addition to those of Doñana and Sierra Morena. This will necessitate an increased emphasis on coordinated conservation action plans, both in situ and ex situ, among the numerous jurisdictions encompassing lynx distributions in Portugal and Spain (Vargas 2000). Figure 4. Phylogenetic relationships among Iberian lynx individuals from three lynx populations based on the proportion of shared alleles among the combined genotypes of 28 microsatellite loci. Among the individuals from the Doñana metapopulation, those from the Coto del Rey population are underlined and those from the Vera population are not. Bootstrap support (100 iterations) between populations is listed. Granqvist 1987; Werderlin 1981). These lynx, often referred to as cave lynx (L. p. speleus), were larger than current L. pardinus. Ecological and biogeographical data suggest that the Iberian lynx was restricted to a glacial refugium in southern Iberia during one or more of the frequent ice periods, as occurred with numerous other species (Bennet et al. 1991; Hewitt 1996), such as the grasshopper Chorthippus parallelus (Cooper et al. 1995) and some shrews of the Sorex araneus group (Taberlet et al. 1994). The relatively low levels of mtdna sequence and microsatellite size variation relative to other cat species in evidence today may have resulted from at least one demographic bottleneck during this time period. Conservation Implications There currently are no recognized subspecies of Iberian lynx. Most of the conservation programs that have been envisaged for the Iberian lynx have been based on metapopulations. These molecular genetic results suggest that there is modest genetic differentiation among microsatellites between Doñana versus Sierra Morena metapopulations. However, the differences are slight and inapparent with mtdna. These results suggest that the overriding genetic concern of Iberian lynx populations may be their small effective population sizes at risk for extinction and further genetic reduction. If current trends continue, it is very likely that much more active management of some populations will be necessary in order to maintain sufficient population sizes and existing levels of genetic variation (Johnson et al. 2001). References Beltrán JF and Delibes M, Physical characteristics of Iberian lynxes (Lynx pardinus) from Doñana, southwestern Spain. J Mamm 74: Beltrán JF and Delibes M, Environmental determinants of circadian activity of free-ranging Iberian lynxes. J Mamm 75: Beltrán JF, Rice JE, and Honeycutt RL, Taxonomy of the Iberian lynx. Nature 379: Bennett KD, Tzedakis PC, and Willis KJ, Quaternary refugia of north European trees. J Biogeog 18: Breitenmoser U and Breitenmoser-Wursten C, Status, conservation needs and reintroduction of the lynx (Lynx lynx) in Europe. Strasbourg, Council of Europe, Nature and Environment Series, no. 45. Castro LR and Palma L, The current status, distribution and conservation of Iberian lynx in Portugal. J Wildl Res 2: Cooper SJ, Ibrahim KM, and Hewitt GM, Postglacial expansion and genome subdivision in the European grasshopper Chorthippus parallelus. Mol Ecol 4: Culver M, Johnson WE, Pecon-Slattery J, and O Brien SJ, Genomic ancestry of the American puma (Puma concolor). J Hered 91: Driscoll CA, Menotti-Raymond M, Nelson G, Goldstein D, and O Brien SJ, Genomic microsatellites as evolutionary chronometers: a test in wild cats. Genome Res 12: Ellegren H, Primmer CR, and Sheldon BC, Microsatellite evolution : directionality or bias? Nat Genet 11: Felsenstein J, Phylogeny inference package (PHYLIP) version 3.5c. Seattle: University of Washington. Ferreras P, Landscape structure and asymmetrical inter-patch connectivity in a metapopulation of the endangered Iberian lynx. Biol Conserv 100: Ferreras P, Aldama JJ, Beltrán JF, and Delibes M, Rates and causes of mortality in a fragmented population of Iberian lynx Felis pardina (Temminck). Biol Conserv 61: Ferreras P, Beltrán JF, Aldama JJ, and Delibes M, Spatial organization and land tenure system of the endangered Iberian lynx (Lynx pardinus, Temminck, 1824). J Zool Lond 243: Gaona P, Ferreras P, and Delibes M, Dynamics and viability of a metapopulation of the endangered Iberian lynx (Lynx pardinus). Ecol Monogr 68: Garcia-Perea R, New data on the systematics of lynxes. Cat News 16: Guo SW and Thompson EA, Performing the exact test of Hardy- Weinberg proportion for multiple alleles. Biometrics 48: Hasegawa M, Kishino H, and Yano TA, Dating of the human ape splitting by a molecular clock of mitochondrial-dna. J Mol Evol 22: Hewitt GM, Some genetic consequences of ice ages, and their role in divergence and speciation. Biol J Linn Soc 58: Hillis DM and Bull JJ, An empirical test of bootstrapping as a method for assessing confidence in phylogenetic analysis. Syst Biol 42:

10 Journal of Heredity 2004:95(1) Huelsenbeck JP, Bull JJ, and Cunningham CW, Combining data in phylogenetic analysis. Trends Ecol Evol 11: Janczewski DN, Modi WS, Stephens JC, and O Brien SJ, Molecular evolution of mitochondrial 12S RNA and cytochrome b sequences in the pantherine lineage of Felidae. Mol Biol Evol 12: Johnson WE, Culver M, Iriarte JA, Eizirik E, Seymour K, and O Brien SJ, Tracking the elusive Andean mountain cat (Oreailurus jacobita) from mitochondrial DNA. J Hered 89: Johnson WE, Dratch PA, Martenson JS, and O Brien JS, Resolution of recent radiations within three evolutionary lineages of Felidae using mitochondrial restriction fragment length polymorphism variation. J Mamm Evol 3: Johnson WE, Eizirik E, Roelke-Parker M, and O Brien SJ, Applications of genetic concepts and molecular methods to carnivore conservation. In: Carnivore conservation (Gittleman JL, Funk SM, Macdonald O, and Wayne RK, eds). Cambridge: Cambridge University Press; Johnson WE and O Brien SJ, Phylogenetic reconstruction of the Felidae using 16S rrna and NADH-5 mitochondrial genes. J Mol Evol 44(suppl 1):S98 S116. Johnson WE, Pecon-Slattery J, Eizirik E, Kim J, Menotti-Raymond M, Bonacic C, Cambre R, Crawshaw P, Nunes A, Seuanez H, Moreira MA, Seymour KL, Simon F, Swanson W, and O Brien SJ, 1999a. Disparate phylogeographic patterns of mitochondrial DNA variation in four closely related South American small cat species. Mol Ecol 8:S79 S94. Johnson WE, Shinyashiku F, Menotti-Raymond M, Driscoll C, Leh C, Sunquist M, Johnston L, Bush M, Wildt D, Yuhki N, and O Brien SJ, 1999b. Molecular genetic characterization of two insular Asian cat species, Bornean bay cat and Iriomote cat. In: Evolutionary theory and processes: modern perspectives (Wasser SP, ed). Dordrecht: Kluwer Academic; Kim J, Eizirik E, O Brien SJ, and Johnson WE, Structure and evolution of the mitochondrial DNA control region in the great cats (Panthera). Mitochondrion 14: Kumar S, Tamura K, Jakobsen IB, and Nei M, MEGA2: molecular evolutionary genetics analysis software. Tempe, AZ: Arizona State University. Kurten B, Pleistocene mammals of Europe. Chicago: Aldine Press. Kurten B and Granqvist E, Fossil pardel lynx (Lynx pardina spelaea Boule) from a cave in southern France. Ann Zool Fennici 24: López JV, Cevario S, and O Brien SJ, Complete nucleotide sequences of the domestic cat (Felis catus) mitochondrial genome and a transposed mtdna tandem repeat (Numt) in the nuclear genome. Genomics 33: López JV, Culver M, Stephens JC, Johnson WE, and O Brien SJ, Rates of nuclear and cytoplasmic mitochondrial DNA sequence divergence in mammals. Mol Biol Evol 14: MacFadden BJ and Galiano H, Late Hemphillian cat (Mammalia: Felidae) from the Bone Valley formation of central Florida. J Paleontol 55: Martin LD, Fossil history of the terrestrial Carnivora. In: Carnivore behavior, ecology, and evolution (Gittleman JL, ed). Ithaca, NY: Cornell University Press; Menotti-Raymond M, David VA, Chen ZQ, Menotti KA, Sun S, Schaffer AA, Agarwala R, Tomlin JF, O Brien SJ, and Murphy WJ, Second generation integrated genetic linkage/radiation hybrid maps of the domestic cat (Felis catus). J Hered 94: Menotti-Raymond M, David VA, Lyons LA, Schaffer AA, Tomlin JF, Hutton MK, and O Brien SJ, A genetic linkage map of microsatellites in the domestic cat (Felis catus). Genomics 57:9 23. Menotti-Raymond M, David VA, Stephens JC, and O Brien SJ, Genetic individualization of domestic cats using feline STR loci for forensic analysis. J Forensic Sci 42: Michalakis Y and Excoffier L, A generic estimation of population subdivision using distances between alleles with special reference to microsatellite loci. Genetics 142: Minch E, Ruiz-Linares A, Goldstein DB, Feldman MW, and Cavalli- Sforza LL, MICROSAT. Available at microsat.html. Nowak RM, Walker s mammals of the world, 6th ed. Baltimore: Johns Hopkins University Press. Nowell K and Jackson P, Wild cats: status survey and conservation action plan. IUCN publications. Cambridge: Burlington Press. Page RD, Tree view: An application to display phylogenetic trees on personal computers. Comp Appl Biosci 12: Palomares F, Delibes M, Ferreras P, Fedriani JM, Calzada J, and Revilla E, Iberian lynx in a fragmented landscape: predispersal, dispersal and postdispersal habitats. Conserv Biol 14: Palomares F, Delibes M, Revilla E, Calzada J, and Fedriani JM, Spatial ecology of the Iberian lynx and abundance of its primary prey, the European rabbit, in a heterogeneous environment. Wildl Monogr 148:1 36. Palomares F, Godoy JA, Piriz A, O Brien SJ, and Johnson WE, Fecal genetic analysis to determine the presence and distribution of elusive carnivores: design and feasibility for the Iberian lynx. Mol Ecol. Palomares F, Rodríguez A, Laffitte R, and Delibes M, The status and distribution of the Iberian lynx Felis pardina (Temminck) in Coto Doñana area, SW Spain. Biol Conserv 57: Pecon-Slattery J and O Brien SJ, Patterns of Y and X chromosome DNA sequence divergence during the Felidae radiation. Genetics 148: Piris AE and Fernandes ML, Last lynxes in Portugal? Molecular aproaches in a pre-extinction scenario. Con Gen 4: Rodríguez A and Delibes M, El lince ibérico en España: distribución y problemas de conservación. Madrid: ICONA-CSIC. Rodríguez A and Delibes M, Current range and status of the Iberian lynx Felis pardina Temminck, 1824 in Spain. Biol Conserv 61: Rodríguez A and Delibes M, in press. Internal structure and contraction patterns in the geographic range of the Iberian lynx. Ecography. Saitou N and Nei M, The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4: Sambrook J, Fritsch E, and Maniatis T, Molecular cloning: a laboratory manual. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press. Schneider S, Roessli D, and Excoffier L, ARLEQUIN version 2000: a software for population genetic data analysis. Geneva, Switzerland: University of Geneva. Slatkin M, A measure of population subdivision based on microsatellite allele frequencies. Genetics 139: Swofford DL, PAUP* phylogenetic analysis using parsimony and other methods. Sunderland, MA: Sinauer Associates. Taberlet P, Fumagalli L, and Hausser J, Chromosomal versus mitochondrial DNA evolution: tracking the evolutionary history of the southwestern European populations of the Sorex araneus group (Mammalia, Insectivora). Evolution 48: Vargas A, Plan de accion para la cria en cautividad del lince Iberico.. Madrid, Spain: Ministerio de Medio Ambiente. Weir BS and Cockerham CC, Estimating F-statistics for the analysis of population structure. Evolution 38: Werderlin L, The evolution of lynxes. Ann Zool Fenn 18: Received February 24, 2003 Accepted August 28, 2003 Corresponding Editor: Rob DeSalle 28